Too Expensive For Black People to Adopt?

Here is a video I found, and my response to this post.
http://www.youtube.com/watch?v=bfVRnOUTg6M

Common responses:

"We [black people] adopt all the time, but it's not centered on paperwork and formalities."

"Black people do adopt, but media sensationalizes those elite white people who rescue [adopt] kids so, people don't hear about what we're doing."

"It's too expensive to adopt."

I am thankful to have heard so many honest responses and am gathering that the definition of adoption differs amongst cultures and ethnic communities. It seems as though the black folks who responded to the last post and in this video feel that adoption means that a biologically related family member would simply take care of a child - short or long term and the lowest two rungs on Maslow's hierarchy of needs being the most important (safety and physiology). In my professional adoption work, and continued involvement with adoption communities, I hear adoption discussed more as a permanent solution, stability and permanency being the pinnacle of the equation, and all of the needs being attended to (security, physiology, social, esteem and self-actualizing).

Thus, I still feel that my basic question has gone unanswered. Not all children are so fortunate to be informally adopted by a relative, so why aren't black families adopting already born children of color through foster care (generally no fees - thus dissuading the argument of the high costs of adoption).?